Now you're talking or asking questions that fellas with experience can help you with . WELCOME to the 10 ga gang as I find it alot of fun loading for this Big Payload shooter . RSI 99 is a very good load to start with and perfect out of your gun / choke combo , I can only suggest with my limited experience , that you designate the loading of the 10 ga as a #1 size shot or bigger gun ! A lot of 10 ga shooters ( I read ) are fixed on BB's , BBB's or T's and that's all their experience says " what works for them " ! Surely in your area , by the type birds you get to shoot at , you'll come up with your favorite......then you can get into the debate ( with the rest of us ) what's the better load . I've found kicking my lips out'a gear and cleaning off my glasses when reading some good info on these forums , have given me some exceptional advise when reloading the 10 ga as we are very fortunate to have so-many longtime 10 ga reloaders to guide us .......!